Elastic Scattering and Single-Pion Production in Proton-Proton Interactions at 6.92BeVc

Elastic scattering and single-pion production in $\mathrm{pp}$ collisions at 6.92 $\frac{\mathrm{BeV}}{c}$ were studied in the BNL 80-in. hydrogen bubble chamber. Partial cross sections for the different final states are given. The reaction $\mathrm{pp}\to nN_{1238}^{}{}_{}{}^{*}\left(p{\pi }^{+}\right)$ with $\sigma =1.9\mathrm{}\pm 0.3$ mb is analyzed and is in agreement with the modified one-pion-exchange model. Single-pion production can be explained as due mainly to two channels: (a) $\mathrm{pp}\to N_{1238}^{}{}_{}{}^{*}\left(p{\pi }^{+}\right)n$, and (b) $\mathrm{pp}\to p\left(n{\pi }^{+}\right)$ or $\mathrm{pp}\to p\left(p{\pi }^0\right)$, where the ($n{\pi }^{+}$) and ($p{\pi }^0$) pairs are in an $I=\frac{1}{2}$ state.